Well pumps



` pumping.

United States Patent lice ananti Patented Dec. 22, 1964 3,162,143 WELL PUMPS Jack B. Ferguson, R0. Box 1711, Houston, Tex., assigner of sixty percent to Robert B. Ferguson, Brazoria, Tex. Filed Ian. 10, 1962, Ser. No. 165,333 11 Claims. (Cl. 10S-179) This invention relates to well pumps, and more particularly it relates to well pumps of the reciprocating submersible type.

In the production of fluids from wells, and particularly oil wells, it has been the common practice to utilize a pump of the reciprocating type which is immersed in the well fluid. The pumping or lifting action is accomplished by reciprocating the connecting or sucker rod which connects the pump in the well with the prime mover on the surface. In order to provide the pumping or lifting action and to prevent reverse flow of the fluid back into the well, a standing or inlet valve is provided on the stationary pump cylinder or working barrel, and a traveling or outlet valve is provided on the reciprocating piston. As the piston begins the upstroke, the standing valve opens to allow the well fluid to enter the pumping chamber and the traveling valve closes to lift the fluid above such outlet valve toward the surface. As the piston begins the downstroke, the standing valve closes to prevent the fluid within the pumping chamber from flowing back into the well, and the traveling valve opens to permit such fluid to pass therethrough and into the conductor or tubing above the traveling valve. The well fluid is thus conveyed or lifted to the surface by repeating the foregoing cycle. Due to the inherent stretch in the sucker rod, the piston must be spaced apart from the end of the cylinder when the piston is at its lowermost position during the downstroke in order to insure efficient and continued If the pump is initially set so that there is no or inadequate clearance between the end of the pump cylinder and the bottom of the piston when the latter is at its lowermost position, then the pump will lobviously be damaged, if not destroyed, upon subsequent elongation or stretching of the sucker rod so that the piston bangs against or drives through the bottom of the pump cylinder before the piston travel reverses to begin the upstroke.

This necessary clearance between the bottom of the pump cylinder and the piston when the latter is at its lowermost position creates a dead space or chamber through which the usual pump piston does not pass during the pumping cycle. If gas is drawn into the pumping chamber on an upstroke of the piston, then there is danger of the pump becoming vapor locked, that is, the gas within the chamber is compressed on the subsequent downstroles of the pump piston and the traveling or outlet valve is not opened when the force due to the pressure in the chamber does not exceed the force created by the column of liquid standing above the outlet valve.

If Well fluid having gas entrained therein is drawn into the pump chamber, then there is again danger ofthe pump becoming vapor locked since the entrained gas escapes when the fluid passes from the high pressure in the well bore to the relatively low pressure within the pump chamber. Thus, thegas within the pump chamber is compressed and expanded during subsequent pumping cycles with little 'or no effective pumping action taking place. Of course, if it were possible to provide a pump without the clearance chamber, then vapor locking would not be a problem since any gas or .frothy well fluid would be forced above the traveling valve before thel pump piston reached the point of zero clearance.

It is therefore a primary object of this invention to the upstroke, the traveling valve 17 elo-ses and the provide a reciprocating type well pump wherein the desired clearance for efficient pumping is provided between the pump cylinder and piston, and yet the pump is incapable of vapor locking when gaseous conditions are encountered.

It is also an object of this invention to provide a reciprocating type well pump wherein a telescoping assembly is provided on one end of the pump piston, said telescoping assembly being in effect a variable extension of the pump plunger which eliminates the clearance chamber and removes any gas or gaseous fluid in said clearance chamber.

It is another object of this invention to provide a well pump of the character described wherein the extensible member of the telescoping assembly contains a check valve which allows any fluid or gas to` pass above such check valve on the downstroke of the pump piston and which prevents the reverse flow of the fluid or gas so that such fluid or gas is elevated or lifted upon the subsequent upstroke of the pump piston and telescoping assembly.

It is another object of this invention to provide a well pump of the character described wherein the extensible member of the telescoping assembly may fall or extend due to its own weight into contact with the stationary member of the pump whereby little or no space remains wherein gas may accumulate to cause vapor locking of the pump.

It is yet another object of this invention to provide a well pump of the character described which is of 'the traveling barrel type, that is, wherein an outer slidable sleeve or barrel encircles a stationary inner piston member.

The construction designed to carry out the invention will be hereinafter described, together with other features thereof. v

This invention will be more readily understood lfrom a reading of the following detailed description and reference to the drawings wherein:

FIGURE l is a sectional illustration of a well pump constructed in accordance with this invention, the piston of said pump .being illustrated at the lowermost position of the d'ownstroke,

FIGURE 2`is a sectional illustration similar to FIG- URE 1, but illustrating the pump piston during the upstroke, and

FIGURE 3 is a sectional illustration of a traveling barrel type well pump constructed in accordance with this invention.

In the drawings, the numeral 10 designates a well pump which includes the usual working barrel or cylinder 11 and piston 12. In the 'embodiment shown in the FIGURES 1 and 2, the cylinder is part of the lower portion of the well tubing 13, which tubing extends to the surface and provides the conductor-for conveying the well fluid to the surface.

The piston 12 is the movable member of the pump in the embodiment shown in FIGURES l and 2, and has sliding and sealing engagement with the bore 14 of the cylinder 11. The piston 12 is connected to the connecting or sucker rod 15 which extends to the surface and is connected to the reciprocating means (not shown) whereby the piston 12 may be moved upwardly and downwardly to provide the necessary pumping action. A pump inlet o-r standing valve 16 which includes an annular seat member 16a is provided at the bottom of the cylinder 11 While a pump outlet or traveling valve 17 is provided at the bottom of the piston 12.

Thev foregoing parts or components of the usual well pump are old and well known in the art, and operate in the following manne-r. As thepiston 12 begins recti'on.

standing valve 16 opens to allow the Well uid to enter the pumping chamber 18 from the well bore 19. As the piston begins its downstroke, the upstanding valve 16 closes and the traveling valve 17 opens whereby the well .fluid within Lthe pumping chamber .18 enters the lifting chamber 19 as the piston moves downwardly. The well yuid in the lifting chamber 19 is forced upward-ly through port 20 into the interior of the tubing 13 by the well fluid entering the lifting chamber 19 through the traveling valve 17. The welluid is thus conveyed to the surface in the tubing 13 upon repeated cycles of the fore- ,going steps.

VAs has been noted, it is necessary toprovide a clear- Vvance space between the bottom of the cylinder 11 and Vlockingis ydue to the compressing of the gas in the clean ance space of the pump chamber during the downstroke of the piston and the inability of the force due to the pressure within the pump chamber acting on the traveling valve to lopen it to overcome the force created by the `uid column above the traveling valve tending to keep it closed. During the upstroke ofthe piston, the gas within ythe pumping chamber simply'expands, and then during the next downstroke, the gas is again compressed with little or no elective pumping action taking'place. Oi course, if an incompressible iuid lls the pumping chamber, then the traveling valve will be opened during `the downstroke.

In the preferred form .of the invention, the foregoing problem of Vapor locking is overcome by providing a telescoping assembly T which effectively extends the lworking area of the piston so that the lower end of the piston at the bottom of its downstroke is adjacent or in close proximityfto the bottom of the cylinder, and any gas or gaseous lluid in the clearance space is picked up and lifted on the next upstroke. The telescoping assembly T inclu'd'esan inner tubular mandrel 121 attached or secured by any suitable means to the bottom of the piston 12 which as shown in FIGURE 1 may be made integral with the piston 12. The bore 22 through the Vmandrel 2,71V communicates with the traveling valve 17 and a radial projection 23, which may be in the form of a flange or lugs, is formed at the lower end of the V,mandrel 21. 4An outer sleeve or extensible member Z5 encircles a portion of the-mandrel 21 andis Vslidable within certain limits thereon. Downward movement of the sleeve relative to the mandrel is limited by the engage Vment of the projection 23 with an inwardly directed annular projection 24 on the outer sleeve 25; when the mandrel is moved upwardly by the piston, a telescoping of the parts occurs until the outer sleeve is picked up and lifted during .tberupstroke of the piston. Downward movement of the outer sleeve. within the cylinder is limited bythe bottom 25a strikingthe standing valvehseat -or working barrel and .has a downwardly seating check valve 26 adapted to engage a seat 29 which surrounds an l inlet passage y27 formed in the lower end of saidV member; 'the valve allo-ws 'the lluid to nov/,therethrough from the pump chamber intothe interior of the sleeve 25 and mandrel 21 while preventingv tlow in` the opposite di- Referring tou 1, thevariousfparts or cornponents are shown in their relative positions when the piston 12 is at the bottom of its downstroke just as it begins the next upstroke. It will be noted that the check valve 26 and the traveling valve 17 close at this point so that the fluidi trapped in the telescoping assembly and above the traveling valve may be lifted during the upstroke. Referring to FIGURE 2 which illustrates the parts during the upstroke, the lugs 23 on the inner mandrel engage the projections 24 on the telescoping member so that the telescoping member is lifted, and the stand ing valve 16 opens in the usual manner to permit huid to enter the pumping chamber.

During the next downstrolte, the traveling valve 17 and the check valve 26 open to permit the fluid within the pump chainber to pass through such valves into the lifting chamber 19 and thence through the port 2G into the tubing 13 whereupon it is conveyed to the surface. The standing valve 16 is closed in the usual manner during the downstroke.

In the event that gas or gaseous well'iluid is drawn into the pumping chamber 13 during a particular upstroke, such gas will. tend to be compressed in the bottom of the pumping chamber 18. The telescoping member 25 will fall of its own weight until the projections 23 and 24 prevent lfurther downward movement or until the bottom of the telescoping member 25 is adjacent the bottom of the cylinder 11, as shown in FGURE l. It is thus apparent that any compressible uid will pass through the check valve 26 as the extensible member 25 drops or falls into a position adjacent the bottom of the cylinder 11. The bottom of the telescoping member 25 may actually contact the bottom of the cylinder 11 and rest thereupon, or it may rest upon any suitable stop means so that it is spaced slightly from the bottom of the cylinder depending upon the particular design of the pump. The compressible fluid is then trapped in the interior of the telescoping assembly by the check valve 26 and will be lifted or elevated during the next upstrolte. Thereafter, such com-pressible uid will be forced eventually into the tubing 13 upon repeated cycles of the pumping operation. Thus a fluid or gas .pocket cannot Vform in the area immediately above the standing valve and the pump is incapable of vapor locking because any compressible iluid entering the pumping chamber 18 on an upstroke will be removed therefrom on a subsequent downstroke by the action of the tclescoping assembly.

In the embodiment shown in FIGURE 3, the telescoping assembly is adapted -for use with a barrel pump. Such barrel pumps are well known in the art and include a stationary piston member 3@ supporting the standing or inlet valve 31, `and a movable cylinder member 32 supporting the traveling or outlet valve 33. The movable cylinder 32 surrounds the piston and is slidable with respect thereto. The stationary piston 3i) is supported by the usual tubing 34 at the bottom thereof by any suitable supporting and sealing means 35 which seals the interior of the wel-l tubing from the well bore 36. The movable cylinder 32 is supported by the connecting rod 37 in the usual manner, land ports, 38 are provided above the traveling valve 33 .so that the well liuid trapped above such valvemay `passinto the interior of the tubing 34. In this type of pump, the necessary clearance space is provided between the standing valve V31 `and the traveling valve 33 sothat when the rsucker rod 37 stretches the two valves will not contact and damage or destroy one another. This pump therefore -is similarly subject to the aforementioned problem of vapor locking.

The telescoping assembly in this .embodiment which overcomes the vapor locking problem, includes the extensible member orsleeve 39 which is interposed between the movable cylinder 32. and the stationary piston 30, and is in sliding and sealing cngagementztherewith, as at 41 and i2/respectively.v The kupper end of the sleeve supports the check valve 40 which allows liuid to flow therethrough from the space` below the valve while preventing reverse ow. An lupset portion ofthe sleeve 39 provides a downwardly-facing external shoulder 43 against which a coacting upwardly-facing internal abutment 44 Iformed in the bore of the movable cylinder 32 engages to lift the extensible sleeve 39 during the upstroke of the movable cylinder 32.

The operation of the telescoping assembly in the barrel pump is quite similar to that of the rst form hereinbebore described. The well fluid in the well bore 36 enters the interior of the stationary piston through the open end thereof. During an upst-roke of the movable cylinder 32, the standing or inlet valve 31 is opened, and the wel] uid flows therethrough into the pumping chamber. As the cylinder 32 begins its downstroke, the standing valve 31 closes and the traveling valve 33 as well as the check valve open to permit the uid in the pumping chamber to pass above the traveling valve 33 and into the interior of the tubing 34 wherein it is conveyed to the surface.

If gas or gaseous uid is drawn into the pumping chamber during an upstroke of the movable cylinder 32 and the extensible member 39, then the compressible fluid will be picked up by the latter upon a subsequent downstroke and will not be trapped in the usual clearance chamber and cause the pump to vapor lock. As the movable cylinder 32 descends during a downstroke, the extensible sleeve 39 will descend therewith until its descent is stopped by the standing valve 31 or by any suitable stop means in close proximity to the standing valve 31; the compressible iluid passing through the check valve 40 into the space above such check valve. If the movable cylinder 32 should continue to descend, then the stationary piston 30 and/or standing valve 31 need only support the weight of the sleeve 39 .and not the excessive weight of the connecting rod as Well as absorb the yforce of the downward movement of the movable cylinder 32 and connecting rod 37.

During the next upstroke of the movable cylinder 32, the abutment 44 will engage the shoulder 43 on the sleeve 39 and cause the latter to be lifted as the cylinder 32. moves upwardly. As the check valve 40 will not allow any iiuid thereabove to flow back into the pumping chamber, then such uid is lifted by the extensible sleeve 39 and removed from the pumping chamber. Of course, the iluid trapped above the check valve 40 will eventually pass into the interior of the tubing 34 through the traveling valve 33 and ports 38 during subsequent cycles of the pumping operation.

The foregoing disclosure and description of the invention is illustrative and explanatory thereof, and various changes in the size, `shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims without departure from the spirit of the invention.

What I claim is:

l. A Well pump including,

a stationary cylinder,

a movable piston in sealing engagement with said cylinder and slidable relative thereto, i

a standing inlet valve supported at the lower end of said cylinder,

said piston being spaced from said standing valve at the completion of the downstroke of said piston,

a rst upwardly opening check valve supported by said movable piston, v

a tubular sleeve telescoping the lower end of the piston and having sealing engagement with said cylinder,

a second upwardly opening check valve supported at the lower end of said sleeve,

means for connecting the said sleeve to said piston whereby said sleeve may undergo limited slidingk and a cylinder pump member movable relative to each other, one of said pump members being stationary and the other pump member being movable, the stationary pump member having a standing inlet valve which is spaced from the end of the movable pump member when the pump is at the limit of its down stroke and the movable pump member having valve means for lifting the well uid during the up stroke, the combination comprising,

means having limited extensible motion connected with the movable pump member and being adapted to move into close proximity to said standing inlet valve of the stationary pump member prior to the completion of the down stroke of the movable pump member whereby the presence of a substantial space between said movable pump member and said stationary pump member is eliminated when the down stroke has been completed to thereby prevent the trapping of compressible iluid in the space between the end of the movable pump member and said stationary pump member,

and check valve means supported by the means which is connected with the movable pump member for permitting ow of tluid past said extensible means during the down stroke of the movable pump member and preventing reverse tlow during the up stroke of the movable pump member wherebyv uid is lifted during the subsequent up stroke of said movable pump member.

3. In a well pump, the combination as set forth in claim 2 wherein said means connected with the movable pump member comprises,

a tubular element having limited extensible movement in a longitudinal direction relative to the movable pump member and having unrestricted movement in a longitudinal direction with respect to the stationary pump member.

4. In a well pump having a movablepump means for lifting the Well fluid and a stationary pump member, the combination comprising,

a telescoping assembly carried by said movable pump means,

means connecting said telescopingr assembly to said movable pump means for relative movement between said telescoping assembly and said movable pump means whereby said telescoping assembly is extensible into substantial engagement with said stationary pump member when said movable pump means is at the end of the pump down stroke,

and valve means supported by said telescoping assembly for permitting the flow of fluid past said telescoping assembly during the down stroke of the movable pump means and preventing reverse liow during the up stroke of the movable. pump means whereby the Huid is lifted during the subsequent up stroke of said movable pump means.

5. A well pump comprising,

a stationary pump member,

a movable pump means for lifting the well uid,

said movable pump meansbeing movable away from i said stationary pump member in an up stroke and movable toward said stationary pump member in a down stroke,

said movable pump means being spaced from said stationary pump member to deiine a pump chamber at the limit of the down stroke of said movable pump means, a standing inlet valve supported by said stationary pump member for admitting the well 'lluid into said pump chamber. v

a tubular mandrel carried by said movable pump means and having uid communication therewith,

, an extensible tubular sleeve having duid communication with said mandrel and mounted on said man-v drel for limited movement relative to said mandrel whereby saidsleeve is lifted during the-up stroke of said movable pump means, y

said sleeve being extensible into said pump chamber within limits relative to said mandrel during the down stroke of said movable pump means,

and valve means supported by said extensible sleeve forjadmitting the iluid within said pump chamber into said sleeve from said pump chamber during the down stroke of the movable pump means and preventing reverse ilow into said pump chamber during the up stroke of the movable pump means whereby duid contained in vsaid vpump chamber is lifted during the subsequent up lstroke of. said movable pump means.

6. A well pump comprising,

a stationarypurnp member,

a movable pump member movable away from said stationary pump member in an up stroke and movable toward said stationary pump member in a down stroke, Y

said movable pump member being in sealing engagement -wi-th said stationary pump member and spaced lfrom said stationary pump. member tofdeline a pump chamberat the limit of vthe down stroke of said movable pump member,

Aa `standing inlet valve supported by said stationary pump member for admitting Well duid into said pump eli-amber,

travelling outlet valve means supported by said movable pump member for lifting well duid duning the Y up stroke= of said movable pump member,

an inner ymandrel connected to* said movable pump member, y i

said inner mandrel having a bore therethrough in fluid communication with said travelling voutlet valve means,

an outer sleeve surrounding said inner mandrel and adapted for limited longitudinal movement relative thereto whereby said sleeve is extensible Within limits finto said pump chamber,

lsaid outer sleeve being in sealing engagement with said stationary pump member,

and check valve lmeans supported by said outer sleeve for admitting `the fluid withinv said pump chamber into the `interior of -said outer sleeve and inner mandrel from the ypump chamber during the down stroke of said movable pump member and preventing reverse J'iow into said .pump` chamber during the up stroke of `said movable ,pump member whereby uid contained in said pump chamber is lifted during the subsequent up stroke of said movable pump member.

7. ln .a well pum-p, the Yctm'rbination as set forth in claim 6 wherein,

said inner mandrel has perforations extending through the wall thereof. 8. In a well pump, the combination set forth in claim 6 together with, Y

Y said stationary piston member in an up stroke andy movable toward said stationary piston member in a down stroke,

Y'said lmovable cylinder member being insealing engage- Iment with -said stationary piston member and spaced f from said stationary piston member to delne a pump "8 chamber at the limit of the down stroke of said movable cylinder member,

a standing inlet valve supported by said stationary piston member for admitting well fluid into said pump chamber,

a travelling outlet valve supported by said movable cylinder member for lifting the Well fluid during the up stroke of said movable cylinder member,

an intermediate member interposed between said stationary piston member and said movable cylinder member in sealing engagement with each of said members,

said intermedi-ate member being connecftible with said movable cylinder member and movable within limits relative to said movable cylinder member into substantial Contact with said stationary piston member in close proximity to said standing inlet valve prior to the completion of the down stroke of said movable cylinder member whereby the normal spacing between said movable cylinder member and said standing inlet valve is substantially eliminated when the down stroke has been completed to thereby prevent the trapping of compressible duid in said space,

and valve means supported by said intermediate member for admitting duid within said Vpump Chamber into said intermediate member from said pump chamber during the down stroke of said movable cylinder memiber and preventing reverse flow into said pump charnber during the up stroke of said movable cylinder member whereby flu-id contained in said pump chamber is lifted during the sub-sequent up stroke of said movable cylinder member.

l0. In a well pump, the combination set fonth in claim 9 together with,

lifting the Well fluid and a stationary pump member, the combination comprising,

a telescoping assembly carried by said movable pump means,

said telescoping assembly being extensible into substantial engagement with said stationary pump member when said movable pump means is at the end of the pum-p down stroke,

:said teleseoping assembly including a member extensible relative to said movable pump means whereby during the up stroke of said movable pump means said `extensible member is lifted, and on the down stroke said extensible member may be extended withk in limits, said extensible member being freely mov- 'able relative to the stationary pump member at all times,

and valve means supported by said telescoping assembly for permitting the ow of fluid past said telescoping assembly during the down stroke of the movable pump means and preventing reverse iiow during the up stroke of the pump means whereby the fluid iS Y ii'fted during the subsequent up stroke of said movable pump means.

References Cited in the file of this patent UNTED STATES PATENTS 2,528,833 Kelley Nov. '7, 1950 2,696,134 Ritchey a Sept. 28, i954 2,985,112 Henry A May 23, 1961 

1. A WELL PUMP INCLUDING, A STATIONARY CYLINDER, A MOVABLE PISTON IN SEALING ENGAGEMENT WITH SAID CYLINDER AND SLIDABLE RELATIVE THERETO, A STANDING INLET VALVE SUPPORTED AT THE LOWER END OF SAID CYLINDER, SAID PISTON BEING SPACED FROM SAID STANDING VALVE AT THE COMPLETION OF THE DOWNSTROKE OF SAID PISTON, A FIRST UPWARDLY OPENING CHECK VALVE SUPPORTED BY SAID MOVABLE PISTON, A TUBULAR SLEEVE TELESCOPING THE LOWER END OF THE PISTON AND HAVING SEALING ENGAGEMENT WITH SAID CYLINDER, A SECOND UPWARDLY OPENING CHECK VALVE SUPPORTED AT THE LOWER END OF SAID SLEEVE, MEANS FOR CONNECTING THE SAID SLEEVE TO SAID PISTON WHEREBY SAID SLEEVE MAY UNDERGO LIMITED SLIDING MOVEMENT RELATIVE TO SAID PISTON, THE LENGTH OF SAID SLEEVE AND THE POSITION OF THE CONNECTING MEANS BEING SUCH THAT AT THE COMPLETION OF THE DOWNSTROKE OF THE PISTON THE LOWER END OF SAID SLEEVE IS IN CLOSE PROXIMITY TO SAID STANDING VALVE. 